In a method for communicating by radio, a receiver receives a first signal at a first radio frequency and determines the received level of the signal.
In radio communication systems, messages, for example comprising voice information, image information, video information, SMS (Short Message Service), MMS (Multimedia Messaging Service) or other data are transmitted via a radio interface between transmitting and receiving station with the aid of electromagnetic waves. Depending on the actual embodiment of the radio communication system, the stations can be different types of subscriber radio stations or radio stations in the network such as repeaters, radio access points or base stations. In a mobile radio communication system, at least some of the subscriber radio stations are mobile radio stations. The electromagnetic waves are radiated with carrier frequencies which are in the frequency band provided for the respective system.
Mobile radio communication systems are frequently embodied as cellular systems, e.g. in accordance with the GSM (Global System for Mobile Communication) standard or UMTS (Universal Mobile Telecommunications System), with a network infrastructure including, e.g., of base stations, facilities for supervising and controlling the base stations and other facilities in the network. Apart from these cellular hierarchic radio networks organized over a wide area (supralocal), there are also wireless local area networks (WLANs) with a radio coverage area which, as a rule, is much more limited in space.
Examples of various standards for WLANs are HiperLAN, DECT, IEEE 802.11, Bluetooth and WATM.
Many subscriber radio stations can communicate in different frequency ranges, if necessary by using different radio technologies. Before such a communication takes place, it is required, as a rule, that the radio station performs measurements on signals of the respective frequency range. However, it is frequently complex for a radio station currently communicating in a first frequency range to perform measurements in a second frequency range.